Door latch



H. G. VOIGHT Jan. 28, 1941.

DOOR LATCH Filed Jan. 8, 1940 2 Sheets-Sheet 1 H. G. VOIGHT 2,230,096

DOOR LATCH Filed Jan. 8, 1940 2 Sheets-Sheet 2 gvvum Patented Jan. 28, 1941 UNITED STATES DOOR LATCH Henry G. Voight, New Haven, Conn., assignor to Sargent & Company, New Haven, Conn., a corporation of Connecticut Application January 8, 1940, Serial No.'312,844

13 Claims. (01. 292-169) This invention relates to door latches, and more particularly to a latch having independently rotatable inner and outer knobs to retract the latch bolt, and means at one side of the door, usually the inside, for dogging the outer knob or in some manner preventing the operation of the latch bolt by the outer knob. As shown. the invention is applied to a socalled tubular lock, that is, one which may .be installed by drilling cylin- 1 drical openings through the edge and face of the door, but it will be understood that the invention is applicable to mortise locks as well.

In the past latches have been made in which the outer knob could be dogged against operation, or in which the outer knob was disconnected from the bolt-retracting means, so that it would turn idly without retracting the bolt. These operations were effected by mechanism at the inside of the door, usually in the form of a depressible plunger which served to dog the knob or disconnect it from the bolt-retracting means. Usually this plunger was releasably held in its operative position and returned to inoperative position either by the turning of the inside knob or by the retraction of the latch bolt. As the inside knob in such instances has usually been left free to turn to retract the bolt, the opening of the door from the inside, for example, would restore the dog to inoperative position.

The present invention has for one of its objects the provision of a door latch having mechanism preventing the retraction of the latch.

by the outside knob, and also having means to hold this mechanism in operative position, which means will be controlled not by the retraction of the latch or by the turning of the inner knob, but rather by the position of the door itself. In other words, when the door is open the dogging mechanism may not be set, but can only be moved to dogging position when the door is closed, and will be released from dogging position when the door is opened.

Another object of the invention is the provision of a door latch having means for pre- 4 venting operation of the latch by the outside knob, the mechanism being so arranged that it can only be set when the door is closed.

More specifically the invention has for its objects the provision of a door latch having inner and outer independently rotatable knobs for retracting the latch, and means for dogging the outside knob against operation, and controlling means for holding the do ging means in operative position. the controlling mans itself only being operative when the door is closed, and beparts to be hereinafter described and claimed. 5

In the accompanying drawings:

Fig. 1 is a side elevational view of a portion of a door-provided with a latch embodying my invention;

Fig. 2 is a face view of the edge of the door;

Fig. 3 is a sectional view on line 3-3 of Fig. 2;

Fig. 4 is a view of the lock case mounted in the door, with the cover removed to show the interior mechanism;

Fig. 5 is a sectional view on line 55 of Fig. 4 but showing the cooperation of the latch bolt with the strike plate on the jamb; and

Fig. 6 is a view similar to Fig. 5 but showing the latch in the position assumed when the door is fully closed.

To illustrate a preferred embodiment of my 'invention I have shown in Fig. 1 of the drawings a portion of a door it, upon which is mounted a latch case II having a face plate l2 secured to the door by screws I3, through which face plate projects a latch bolt i4. As shown in Figs. 5 and 6, the latch bolt is adapted to cooperate with a strike plate [5 having an opening I6 to receive the bolt.

The latch case is shown more particularly in Figs. 3 to 6, from which it will be observed that the case is of a form to be received in a'cylindrical bore in the edge of the door. The bolt I4 is slidably mounted inthe case and is provided with a retracting member in the form of a bifurcated stem or yoke having legs I! and I8 provided with laterally turned end portions l9 and 20 adapted to be engaged by rollbacks 2| and 22, which rollbacks are attached to hubs 23 and 24 rotatably journaled in openings in the walls of the case.

The bolt I4 is urged to protracted position by a spring 25 located between-thelegs l1 and I8 and acting against a post 26 extending from one of the walls of the case. The case itself may be formed into two parts, one of which 21 serves as a cover and is held in place at its forward end by 2. lug 28 on the other part of the case, and at its rear end by the screw 29.

Upon the door are mounted inner and outer roses 30 and 3|, in which inner and outer knobs 32 and 33 are rotatably mounted. To these knobs are secured respectively the non-circular spindles 34 and 35, the inner ends of which are respectively received in the hubs 23 and 24. The

spindles 34 and 3,5 are independently rotatable, as of course are the hubs 23 and 24, and the spindles may for this purpose have a screw-threaded connection 36 at their inner ends.

From the above description it will be apparent that the latch may be retracted by either of the knobs, and that the rotation of one knob will be entirely independent of the movement of the other;

It will be noted from Fig. 3 that the rollback 22 carried by the outer knob is slightly larger than the rollback 2|, so as to project toward the latch bolt to a greater extent than the other rollback, and that this portion of the .rollback 22 is provided with a recess 31, which is adapted to. receive a detent 38 carried by a do ging plunger 39 movably mounted in the walls oi. the lock case, so

that this plunger can bemoved to a position in' which the detent will not be engaged in the recess 31, or in a positionin which such engagement is etlected. The plunger 39 carries a laterally extending block 48 against which acts a spring 4| to normally urge the plunger toward the right, as shown in Fig. 3, or to inoperative position. A push button or manually engageable member 42 may be screw-threaded into the plunger and extend through the rose 30 of the inner knob, where it may be manually engaged to move the plunger from one position to the other. If desired, the outer rose may be provided with a small opening 43, through which a proper tool may be inserted to engage the end of the dogging plunger 39 to push it inwardly to inoperative position. The push button 42 may be provided with agroove 44 with which is engaged a corresponding projection 44 on the rose 38 to prevent rotation of the button and consequent detach ment from the plunger.

It will be apparent that the spring 4| urges the plunger 39 to inoperative position in which both knobs are free to turn, and if it is desired to dog one of the knobs, such, for example, as the outer knob, it will be necessary to provide some means to hold the plunger in operative position against the tension of the spring.

For this purpose recesses 45 are provided in one side of the plunger, in which is adapted to be received a ball 46 mounted in the head 48 -01 the stem 41 of a controlling plunger reciprocably mounted in the lock case. This stem 41 istelescopically received in a hollow cylindrical member 48, which, with the head 46*, is slidably mounted in a bore 48 formed in the lock casing, and projects from the face plate thereof at the rear side of the latch bolt l4. As shown in Figs. 3, 5 and 6, the latch bolt is provided with a recess 49 to receive a portion of the member 48, so that the remainder of this member will project from the bolt to engage the strike plate I 5 on the door jamb, as shown more particularly in Fig. 6. Between the stem 41 and the member 48 which form the other part of the controlling plunger is a spring 50, acting to project the stem from the cylinder or to spread these members apart, and it will be noted that the recess 49 does not extend through the edge of the latch bolt, but is provided with a forward shoulder 5| to act as a stop for the member 48 and to limit the position of this member under the action of the spring 58.

As will be apparent from Fig. 3, when the door is open the latch bolt will be protracted by the spring 25, and the cylindrical member 48 will be moved outwardly against the shoulder 5| by the spring 58. In this position the spring 58 will place very little pressure; upon the ball 46, so that contact with the edge of the strike plate and be the engagement of this ball within the recess 45 will be insuflicient to hold the dogging plunger 39 in its inner operative position against the action of spring 4|. When, however, the door is closed, the member 48 will be cammed inwardly with the 5 latch bolt l4, as shown in Fig. 5, until, when the door is fully closed, as shown in Fig. 6, the latch bolt springs outwardly into the strike opening i5, but the projecting portion of the member 48 will held in a retracted position. In this position the spring 58 is compressed, and the ball 45 will be forced into the recess 45 with sufllcient force to hold the dogging plunger 39 in its operative position against the pressure of the spring 4|.

When the door stands in open position the parts are in. the position shown inFig. 3, and from the previous description it will be understood that it is impossible to set the dogging plunger 39 to dog the outside knob. If the plunger is pressed inwardly at that time it will be immediately forced outwardly again by the spring 4|, so that this pl y be set only when the door is closed. When the door is closed the parts stand in the position shown in Fig, 6, with the stem 41 pressed rearwardly by the spring 59. If the plunger 39 is now depressed by the push button 42, the pressure of the ball in the recess 45 will be suflicient to hold it in operative position, wherein the outside knob will be dogged 3 against movement by reason of the fact that the detent 38 stands in the recess 31 of the outside rollback. It will also be apparent that when the dog is thus set its position will not be changed either by rotation of the inner knob or by the retraction of the latch bolt, but the dogging plunger will only be released, to be returned to inoperative position by the spring 4|, by the opening of the door, that is, the movement of the latch bolt away from the strike plate so that 49 the member 49 can be again projected to relieve the pressure of the spring 58 upon the stem 41.

It will also be observed that the holding of the doggin plunger 39 by the ball 46 is a releasable one rather than a positive one, and that when the door is closed and the dogging mechanism set, the plunger 39 may, by the insertion of a suitable tool through the opening 43, be pushed to inoperative position, so that in case of an e gergency the door may be opened from the outs1 e. v While I have shown and described a preferred embodiment of my invention, it will be understood that it is not to be limited to all of the details shown, but is capable of modification and variation within the spirit of the invention and within the scope of the appended claims.

What I claim is:

1. In a door latch, acasing, a latch bolt reciprocably mounted therein, individually rotatable inner and outer knobs, means operatively connecting each of said knobs with the bolt, an element mounted in the casing and movable transversely of the bolt movement to position to prevent operation of the bolt bythe outside knob, and means to frictionally hold said element in operative position, said means projecting through the face of the casing to be released by the opening of the door.

2. In a door latch, a casing, a latch bolt reciprocably mounted therein, individually rotatable inner and outer knobs, means operativelyconnecting each of said knobs with the bolt, a springpressed element mounted in the casing, means projecting from the casing to move said element 75 ing of the door, to position to prevent retraction of the bolt by the outer knob, said means being accessible for engagement at the inside of the door, and means for holding said movable means in operative position, said holding means itself being held in position to operatively engage said movable means by engagement with the strike 4 plate.

4. In a door latch, a casing, a latch bolt carried thereby, individually rotatable inner and outer knobs, mechanism actuated by each knob for retracting the bolt, dogging means projecting from the inner face of the door for manual engagement to prevent operation of the bolt by the outside knob, controlling means to hold said dogging means in operative position, said controlling means having a part projecting through the edge of the door to be moved to operative position when the door is closed, and said dogging means being movable to dogging position after the controlling means is moved to operative position.

- 5. In a door latch, a casing, a latch bolt carried thereby and adapted to cooperate with a strike plate, independently rotatable, inner and outer knobs, mechanism actuated by each knob for retracting the bolt, doggingmeans to prevent operation of the bolt by the outside knob and movable to operative position after the door is closed, and controlling means to hold said dogging means in operative position, said controlling means being itself moved to operative position by engagement with the strike plate, and said dogging means being accessible for engagement at the inside of the door.

6. In a door latch, a casing, a latch bolt carried thereby and adapted to cooperate with a strike plate, independently rotatable inner and outer knobs each of which is connected to the latch bolt to operate the same, a dogging member movably mounted in the lock case and movable to position to dog theouter knob against movement, a member spring-pressed into engagement with said dogging member to hold' the latter in operative position, and an element projecting through the face of the casing to increase the tension of said spring when the door is closed.

7. In a door latch, a casing, a latch bolt carried thereby and adapted to cooperate with a strike plate, independently rotatable inner and outer knobs each of which is connected to the latch bolt to operate the same, a dogging member movably mounted in the lock case and movable transversely of the bolt movement to position to dog the outer knob against movement, and a dog-controlling plunger having a member spring pressed toward a position to engage the dogging member and hold it in operative position, and said plunger having means to engage the strike plate when the door is closed to be forced thereby into opera-v tive engagement with the dogging member.

8. In a door latch, a casing, a latch bolt carried thereby and adapted to cooperate with a strike plate, independently rotatable inner and outer knobs each of which is connected to the latch bolt to operate the same, a dogging member movably mounted in the lock case and movable transversely of the bolt movement to position to dog theouter knob against movement, a dogcontrolling plunger having a member spring 5 pressed toward a position to engage the dogging member and hold it in operative position, said plunger having means to engage the strike plate when the door is closed to force said springpressed member into operative engagement with the dogging member, and a spring urging said dogging member to inoperative position.

9. In a door latch, a casing, a latch bolt carriedthereby and adapted to cooperate with a strike plate, independently rotatable inner and 15 outer knobs each of which is connected tothe latch bolt to operate the same, a dogging member movably mounted in the lock case and movable to position to dog the outer knob against movement, controlling means to engage said member and 20 hold it in operative position, said controlling means comprising a spring-pressed member to engage the dogging member, and a spring-tensioning member adapted .to engage the strike plate.

10. In a door latch, a casing, a latch bolt carried thereby and adapted to cooperate with a strike plate, independently rotatable inner and outer knobs each of which is connected to the latch bolt to operate the same, a dogging member 30 movably mounted in the lock case and movable to position to dog the outer knob against movement, controlling means to engage said member and hold it in operative position, said controlling means comprising a spring-pressed member to engage the dogging member, and a member projecting from the face of the lock to engage the strike plate and be retracted thereby to tension the spring of the spring-pressed member.

11. In a door latch, a casing, a latch bolt car- 40 ried thereby and adapted to cooperate with a strike plate, independently rotatable inner and outer knobs each of which is connected to the latch bolt to operate the same, a dogging member movably mounted in the lock case and movable engage the dogging member, a second member 50.,

movably mounted in the lock. case and adapted to project from the face thereof to engage the strike plate, and a compression spring mounted between said members whereby the first member will be spring-pressed into engagement with the clogging member upon the closing of the door.

12. In a door latch, a casing, a latch bolt carried thereby and adapted to cooperate with a strike plate, independently rotatable inner and outer knobs each of which is connected to the latch bolt to operate the same, adogging member movably mounted in the lock case and movable to position to dog the outer knob against movement, controlling means for said dogging member, said controlling means comprising a springpressed member projecting from the lock case to engage the door strike and be retracted thereby, and a second spring-pressed member actuated by the first into operative engagement with the dogging member.

13. In a door latch, a casing, a latch bolt carried thereby and adapted to cooperate with a strike plate, independently rotatable inner and outer knobs each of which is connected to the movably mounted in the lock case and movable to position to dog the outer knob against movement, a dogcontrolling member, a spring urging said dog-controlling member into engagement with the dogging member, a. spring normally urging said dogging member to inoperative position,

and means actuated by the closing of the door to tension said first spring whereby the dogging member is held in operative position, against the tension of said second spring.

HENRY G. voIGm'. 

